A Regime is the set of structures a Discipline stabilizes — everything that remains fixed under a Discipline’s pattern.
If a Discipline is a structural pattern compatible with Flow and Nucleus, a Regime is the domain that pattern governs — everything that persists under that discipline. A Regime is what the world looks like from the perspective of a particular Discipline: the structures it preserves, the regularities it maintains, the domain of stability it carves out.
Different Disciplines produce different Regimes — different stable domains within the same Geometry. The richness of Geometry shows up in the variety of Regimes it can support.